Accession Number:

AD0702896

Title:

MICRODYNAMICS OF WAVE PROPAGATION

Descriptive Note:

Annual summary rept. Jun 1967-Jun 1968

Corporate Author:

WHITTAKER CORP SAN DIEGO CA NARMCO RESEARCH AND DEVELOPMENT DIV

Report Date:

1968-10-01

Pagination or Media Count:

234.0

Abstract:

Part I of this report covers the problem of free and forced vibration of a unidirectional, multifiber reinforced composite. A theoretical investigation is conducted through the use of the linear theory of elasticity. For this case, the geometrical array of the fiber representative element consists of a circular, inner solid fiber cylinder bounded by and bonded to a circular outer matrix shell. Composites of infinite, finite, and semi-infinite lengths are treated. It is assumed that the deformation is axisymmetrical and that the vibration is longitudinal. Characteristic equations are established which relate circular frequencies to axial wave numbers for three cases of composite length. Solutions are obtained for stresses and displacements of composites, of finite or semi-infinite length, subjected to axial, piecewise- constant, or sinusoidal loading at one end and different geometrical boundary conditions at the other. Part II presents an approximate differential equation based on the Bernoulli hypothesis of deformation. The solution of this equation is established for steady and transient states of vibration in composites of both finite and infinite length. Computation of the coefficients in the differential equation is performed by assuming symmetry of revolution for the basic element and also by using a hexagonal fiber arrangement. Part III lists numerical results based on the equations developed in Parts I and II. The appendixes to this report give the computer programs used to perform the computations.

Subject Categories:

  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE